Olfactory and Gustatory Function in Patients With Different Types of Maxillofacial Trauma.

OBJECTIVES/HYPOTHESIS: To investigate olfactory and gustatory function in patients with maxillofacial trauma and associated fractures. STUDY DESIGN: Retrospective cohort study. METHODS: Olfactory and gustatory function was assessed psychophysically in 124 patients who had sustained maxillofacial trauma with an associated fracture. Five groups were defined based on the fracture type: Le Fort, mandibular, nasal, orbital, and zygomatic. Olfaction was measured with Sniffin' Sticks (threshold, discrimination, identification [TDI] score) and gustation with the taste spray method. Patients self-rated olfactory and gustatory function on a visual analog scale prior to formal testing. RESULTS: Ten out of 124 patients were found to be anosmic (8%), with half of them found in the Le Fort (skull base) group. The Le Fort fracture group had significantly lower olfactory function than other fracture types (TDI score = 22.4 ± 10.7; P = .01; possible range = 1-48). The mean gustatory spray test score was 3.82 ± 0.4 (possible range = 0-4) without any intergroup differences. Self-rated olfactory function showed a correlation with the measured scores (r = 0.61, P < .001) across all groups. CONCLUSIONS: The present data show a significant effect of maxillofacial fracture type on the development of anosmia. Maxillofacial fractures involving the skull base, such as Le Fort fractures, are more likely to cause permanent smell loss, whereas the other fracture types are rarely associated with anosmia. LEVEL OF EVIDENCE: 4 Laryngoscope, 131:E331-E337, 2021.

Olfactory Fluctuation Revisited.

OBJECTIVES: Many patients complain about olfactory fluctuation (OF), which is a symptom commonly attributed to sinonasal disease. Data-based evidence for its association with sinonasal disease is scarce. The aim of the study is to identify explanatory variables associated with OF and to analyze its predictive value regarding sinonasal disease. STUDY DESIGN: We performed a retrospective study based on patients with olfactory dysfunction. METHODS: We analyzed data from 482 patients attending the smell and taste outpatient clinic with full psychophysical workup and structured questions regarding their symptoms. The questionnaire included items on OF and chronic nasal symptoms. Clinical investigators filled out the second part of this questionnaire that included information about nasal endoscopy, psychophysical tests of orthonasal olfaction (Sniffin' Sticks), retronasal olfaction, and putative etiology of olfactory dysfunction. RESULTS: OF was more prevalent in sinonasal disease (42.4%) compared to other putative etiologies of olfactory dysfunction such as postinfectious (28%) or posttraumatic (11.7%) (X2 [5, n = 440] = 24.98; P < .0001). OF was strongly associated with Sniffin' Sticks score categories (anosmia, hyposmia, normosmia) (X2 [2, n = 424] = 39.21; P < .0001; Cramer's V = 0.30; P < .0001) and presence of "chronic nasal symptoms" (X2 [1, n = 437] = 22.71; P < .0001; Cramer's V = 0.23; P < .0001). The accuracy in predicting putative sinonasal disease etiology when OF was present depended strongly on the clinical context. CONCLUSION: Olfactory fluctuation is a symptom mostly but not exclusively associated with sinonasal disease, elevated Sniffin' Sticks test scores, and is frequently accompanied by other nasal complaints. Its presence is valuable information for clinicians to be integrated into the clinical context when doing patients' workup. LEVEL OF EVIDENCE: 4 Laryngoscope, 130:2442-2447, 2020.

Chemosensory decrease in different forms of olfactory dysfunction.

The aim of this study is to investigate the effect of olfactory dysfunction (OD) on the two other chemical senses, namely gustation and the intranasal trigeminal system. Taste and trigeminal function were analyzed in a retrospective cross-sectional study of 178 participants with OD (n = 78 posttraumatic, n = 42 idiopathic, n = 27 post-infectious and n = 31 chronic rhinosinusitis (CRS) OD). All patients had been investigated for OD at our smell and taste outpatient clinic. Evaluation of olfaction was performed by means of the Sniffin' Sticks test (odor threshold, odor discrimination and odor identification), whereas gustatory function was assessed with the Taste Strips test and the intranasal trigeminal sensitivity by means of the lateralization task. The degree of olfactory impairment was found to depend on the cause of OD, but not on patients' age. Patients with posttraumatic OD showed lower olfactory function than patients with idiopathic, post-infectious and CRS OD (p = 0.01). Gustatory and trigeminal sensitivity in turn depended on age rather than the cause of olfactory dysfunction. Partial correlations between olfactory, gustatory, and trigeminal scores, with age as covariate, were significant, showing a decrease of taste and trigeminal function proportional to the OD (p < 0.05). The present data suggest that the three chemical senses are closely connected for humans underlining that in case of OD the remaining chemical senses (taste, trigeminal function) tend to decrease rather than compensate as this is seen for sensory loss in other modalities. This finding has direct clinical implications and importance when dealing with smell and taste disorders.

Olfactory function improves following hemodialysis.

Olfactory function has been shown to be affected in chronic kidney disease; however, studies are contradictory and little is known on the effects of dialysis. To resolve these issues we tested olfactory function in 24 healthy controls and in 28 patients with chronic kidney disease receiving hemodialysis (20 patients) or peritoneal dialysis (the other 8). As assays for olfactory function we measured smell identification, n-butanol and acetic acid thresholds, Kt/V urea, percentage reduced urea, and weights before and after dialysis. Olfactory function was also self-rated by the participants. Compared to healthy controls, predialysis olfactory function was moderately but significantly decreased in the two dialysis groups, with hemodialysis patients being more affected. Patients self-rated olfactory function similar to that of healthy controls, suggesting that patients are unaware of the olfactory decrease. Olfactory function was significantly improved by one hemodialysis session. Neither body mass index, total volume loss, nor any other dialysis parameter correlated with olfactory function or its restitution following hemodialysis. The observed pattern of improvement suggests underlying mixed peripheral and central mechanisms. Thus, olfactory dysfunction in patients with chronic kidney disease is readily reversible by hemodialysis.

Olfactory disorders: the patients' view.

OBJECTIVE: To investigate the level of knowledge that patients had about their olfactory disorder at the time of presentation to a specialist Olfaction Clinic. DESIGN: Multi-centered, cohort study of consecutive patients presenting to specialist Olfaction Clinics surveyed using a standardized questionnaire. SETTING: Tertiary referral Olfactory Clinics in Geneva, Switzerland and Dresden, Germany. MAIN OUTCOME MEASURES: The number of prior medial consultations, the number and type of doctors they had consulted, a rating of the information they had received from these doctors, whether prognostic information had been given and whether they felt their problems had been well managed by the doctor were factors surveyed. Olfactory assessment was measured by the Sniffin' Sticks kit. RESULTS: Eighty percent of patients had sought previous medical advice, with a mean 2.1 past consultations. Of these patients, 60 % reported that they had received either no or unclear or unsatisfactory information about their diagnosis, 30% had received no information about their prognosis and 25 % felt they had not been managed well. CONCLUSION: The majority of patients with olfactory disorders seek medical advice before presenting to a specialist Olfaction Clinic. However, the majority reported receiving no or poor information about their diagnosis and prognosis. Considering the significant prevalence and potential consequences of olfactory disorders, it is our duty as specialists to improve the knowledge and communication of our medical colleagues about these diseases, so that patient education or referral can be improved.

Retronasal olfactory function in Parkinson's disease.

OBJECTIVES/HYPOTHESIS: Orthonasal olfaction is severely altered in PD patients. Retronasal olfactory function has been shown to be preserved under certain conditions even in the absence of orthonasal function. This study was undertaken to investigate retronasal versus orthonasal olfactory function in Parkinson's disease (PD). STUDY DESIGN: Prospective study. METHODS: A total of 45 PD patients (mean age, 61 years; range 26-82 years) underwent orthonasal olfactory testing with a standardized olfactory test (Sniffin' Sticks) and retronasal olfactory testing with a 10-item identification kit based on aromatized powders. RESULTS: Regarding orthonasal tests, all PD patients scored within the range of hyposmia and functional anosmia. The mean correct orthonasal identification score for PD patients was 56% +/- 2.6%, and the mean retronasal identification rate was 60% +/- 3%. There was no significant difference between ortho- and retronasal odor identification (P = .15). CONCLUSIONS: The present study shows that retronasal and orthonasal olfactory function are severely impaired in PD patients, and this impairment is of similar magnitude for both functions. The contribution of this finding to the food-intake behavior of PD patients is discussed.

Gustatory function after microlaryngoscopy.

CONCLUSION: Quantitative gustatory alterations are rare after microlaryngoscopy (MLS), whereas transient qualitative taste distortions occur more often. Patients undergoing MLS should know that mild but transient qualitative taste disorders may occur. OBJECTIVE: Suspension MLS requires neck extension and tongue compression. Little is known about taste disorders following MLS. To investigate qualitative and quantitative gustatory function after MLS we tested and questioned patients before and several weeks after the MLS. SUBJECTS AND METHODS: This was a prospective controlled study carried out in a tertiary care centre. Forty-three patients participated, 33 of whom underwent MLS and 10 septoplasty. Tongue compression time was recorded during MLS. Patients received taste evaluation before and at 1 and 14 days after the intervention. Patients were asked to indicate subjectively changed taste perceptions. RESULTS: Psychophysical (quantitative) taste results showed no significant differences before and at 1 and 14 days after the intervention (p = 0.60). Tongue compression time (MLS group) had no influence on measured post-MLS taste scores. In the MLS group four patients reported distorted taste perception the day after the MLS, whereas no patient in the septoplasty group did so. In all, four patients distorted taste perception, had disappeared after 14 days.

Retronasal olfactory function in nasal polyposis.

OBJECTIVE: To investigate the question of whether there is a difference in retronasal olfactory function between patients suffering from chronic rhinosinusitis with nasal polyposis (NP) and healthy controls. This question was based on the clinical observation that many of these patients present with smell loss without complaining about loss of the appreciation of foods. STUDY DESIGN: Open prospective study comparing symptomatic patients with healthy controls. METHODS: A total of 56 healthy volunteers and 42 NP patients were tested for orthonasal and retronasal odor identification. All subjects received detailed nasal endoscopy; NP was staged according to the Malm classification. Patients rated their olfactory function on visual analogue scales. Orthonasal testing was performed using the "Sniffin' Sticks" test kit. Retronasal testing was evaluated with odorized powders applied to the oral cavity. In both tests, subjects were asked to identify 10 items using a forced choice paradigm. RESULTS: Overall, odor identification was better in controls compared with NP patients (P <.001). Although controls exhibited no difference between orthonasal and retronasal smelling (P =.26), in NP patients, olfactory function was significantly better when odors were applied through the retronasal route (P <.001). Ratings of general olfactory abilities correlated with retronasal and orthonasal olfactory function in NP patients (P <.001) but not in healthy controls (P =.34). CONCLUSION: Better retronasal than orthonasal olfactory function seems to be associated with the presence of mechanical obstruction in the anterior portion of the olfactory cleft. In turn, these data indicate that olfactory loss in NP seems to be caused by regional mechanical or inflammatory factors.